In the Weddell Sea almost everything shifts, breaks, gets mixed up. From afar, floating ice, accumulated snow and frost-covered surfaces end up looking alike, and the eye gets used to that continuous white that erases the contours. During a patch of bad weather, as the icebreaker Polarstern sought shelter downwind of Joinville Island, a dirty, stationary shape broke that monotony. It looked like one of the many blocks dragged by the water. She remained there, nailed. From that detail, an Antarctic island emerged that the maps did not yet register as a real coast.
On board they moved with caution. The navigators always kept at least 50 meters of water under the keel, managing to get close to around 150 metres. At that point the ship slowly circled the relief, the seabed was measured with the on-board multibeam echo sounder and a drone collected the images necessary to reconstruct the altimetric model and coastline. The result gave precise shape to an object that had until then remained in a sort of gray area: the island measures approximately 130 meters long, 50 meters wide and protrudes 16 meters above sea level. Ice and snow cover much of the surface, and it is precisely this white skin that has camouflaged it so well among the icebergs in the area.
On the nautical charts that stretch already appeared as an area with dangers for navigation, but without a clearly marked island. There was also another difference: the indicated position was shifted by about one nautical mile, therefore more or less 1.8 kilometres, compared to the real point. Satellite images had contributed little, because the ice coating made it almost indistinguishable from nearby floating bodies. Now the official naming procedure opens, and only after that step will the exact position enter international databases and maps used by ships. Boris Dorschel-Herr, who leads the bathymetric work of the expedition, had already followed the inclusion of two seamounts in the maps of the South Atlantic and the Weddell Sea in the past.
A useful discovery also for navigation
The geographical surprise came during a mission that had another objective: to follow the outflow of water and ice from the Larsen shelf, one of the sectors that influence global ocean circulation. The international team, 93 people aboard the Polarstern, had been working in the northwestern sector of the Weddell Sea since February 8, 2026, in an area crucial to understanding how cold water masses move between the deep sea, the continental shelf and the ice margin. The same surveys helped narrow down the paths by which cold water exits the Larsen Ice Shelf and compare the data collected with oceanographic series followed by AWI since 2002.
Sea ice also comes into play here, which for years in Antarctica has given the impression of greater stability than in the Arctic. That balance has broken. In the northwestern Weddell Sea, summer ice extent has fallen sharply since 2017, with warmer surface water likely playing a role. The measurements collected during the expedition show a very irregular mosaic: on the shallow western continental margin, the ice reached up to 4 meters thick due to the deformations caused by tides and the nearby coast; further east, where the ice came from the large Ronne and Filchner platforms, the thickness dropped to around 1.5 meters and the structure appeared less deformed.
Under the geographical surprise moves a changing polar system
The surface of the ice told yet another story. In many areas the snow was sparse, the color tended towards bluish or gray and signs of melting were evident, albeit with few real surface puddles. Thanks to new turbulence and biological probes, researchers have detected significant amounts of fresh melt water in and under the ice. These cooler layers work like a barrier: they keep the heat of the ocean below away from the ice, influence the rate of melting, and also change the conditions in which life associated with the ice and the sea immediately beneath it develops.
The SWOS expedition closed on 9 April 2026 in the Falklands, after 61 days at sea and 4,444 nautical miles of sailing, and data analysis will continue in the coming weeks. This very concrete image remains: in one of the most studied areas of the planet, an island left at the edge of the maps, covered in ice just enough to disappear into the background, can still pop up. All it takes is for the landscape to stop moving for a moment, and everything changes.
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